MASS-TRANSPORT INVESTIGATED WITH THE ELECTROCHEMICAL AND ELECTROGRAVIMETRIC IMPEDANCE TECHNIQUES .2. ANION AND WATER TRANSPORT IN PMPY AND PPY FILMS

Water transport during anion transport in poly(N-methylpyrrole/nitrate ) (PMPy/NO3), poly(N-methylpyrrole/chloride) (PMPy/Cl), and poly(N-met hylpyrrole/sulfate) (PMPY/SO4) films, where ion transport is anion-spe cific, has been investigated by comparing electrical responses with gr avimetric responses in the cyclic electrochemical quartz crystal micro balance (EQCM) experiment and the impedance experiment. It is shown th at the number of accompanying waters per Cl- or SO42- is considerable, whereas the number per NO3- is nor large. The number of accompanying waters per anion does not change extensively with the concentration of an electrolyte solution and the applied potential. Moreover, the poss ibilities of OH-, H+, cation, and water transport in poly(pyrrole/nitr ate) (PPy/NO3) and poly(pyrrole/chloride) (PPy/Cl) films, where ion tr ansport is not anion-specific, have also been investigated. It is foun d that OH- moves competitively with NO3- or Cl- during their redox rea ction.